Improvement in turbine water-wheels



ttitrd gaat stent attira Letters Patent N 93,175, dated August 3, 1869.

IMPROVEMENT IN TURBINE WATER-WHEELS.

The Schedule referred to in these Letters Patent and making part of`the same.

Beit known that I, JOHN CHASE, of the city of Paterson, in the county of Passaic, and Stateof New Jersey, have invented an Improvement in rIurbine Tater-Wheels, by the use of which a saving and eccnomizing of water-power can be accomplished; and I do hereby declare that the following is a full, exact, and clear description of the construction and operation of the same, reference being had to the vannexed drawings, making part of this specification.

Description of Drawings.

Figure 1 is a plan of the wheel, with part of the chamber broken away.

Figure 2 is an elevation ofthe wheel, partly in section.

Like letters refer to like points.

L L is the chamber.

S, the shaft.

G, the guide.

I, the pivot and step for the same.

fr c c t, the wheel, of which fr f t tis the upper drum, and t' 't' the lower o1' annular drum.

t p is an average o1" mean spira-l element of the vane It.

t q, a line in a vertical radial plane.

r r, upper circumference of upper drum.

c r, circumference of lower drum, (external.)

a n, circumference of lower drum, (internal.)

L k, intermediate between these, or mean radius of annular drum.`

Nat-ure of the Invention.

'It is evident, that in an ordinary' turbine waterwheel, the upper particles of water have less velocity than the lower particles, and that in order to prevent the former from being uselessly .and detrimentally dragged around between the vanes or buckets by the rgreater force or velocity of the latter, thus producing a loss of water-power, the former must be made to act upon portions of the va-nes or buckets having less circumferential velocity than have the portions 'against which the latter act.

Now the object ofmy invention is to avoid' this loss of water-power, which occurs in turbine water-wheels ofthe ordinary form; aud

Its nature consists, iirst, in constructing the wheel lwith a varying diameter, diminishing from bottom to top; and second, iu combining such a wheel with a cylindrical annular wheel of the ordinary form and construction.

In' order to enable those skilled in the art to make and use my invention, I will proceed to describe its construction and operation. i

Description, of Wheel. Upon the shaft S, I x the annular drum, t' r, corresponding to the annular drum or bucket-chamber of an ordinaiy turbine water-wheel with downward discharge, and containing the vanes or buckets, g, &c;, placed at proper angles or inclinations for the securing of an economical action of the water.

Above this annular drum c e, I place atlosed'drum, fr ft t, of variable diameter or circumference,. starting it with a diameter or circumference 4at the base' f equal to that of the inner'wall or rim of the l annular' drum ce, and thence diminishing it' in diameter or circumference up tol the head fr t; and around this upper drum I continue, on the outside, the vanes or buckets of theannular drum in continuous spirals to the head 1^ t, but slightly decreasing the width-of the said vanes or buckets as they approach the head /r t, because of a greater ow of water at the bottom than at the top. It is evident, then, 'that when the wheel is working, the points on the smaller or upper parts of the drum, being nearer the axis of rotation, will have less actual circumferential velocity than the points ou the lower parts of said drum', which `are further from the axis of rotation. The said upper drum is therefore made of such form or shape, -that when the wheel is working, the actual circumferential velocity of the centres of pressure of the vanes or buckets, at each level in the height of the same, shall be directly pro. portional to the velocity of water due to the height of water or hydrostatic head at such level; or, in other words, at each level in the height of the upper drum, the perpendicular distance from the axis of the drum to the centre of pressure of a vane or bucketv sha-ll be directly proportional to the velocity' of water due to the height of water or hydrostatic head at such level. The shape of the upper drum will be that of a spindle or frustum of a spindle with vertical axis.

In ordinary cases the upper drum may be made in the shape of the -frustum of a cone, having the upper and lower diameters of such size as to satisfy the abovementionedA proportion, giving suicient accuracy when so made.

In the language of descriptivegeometry, the surface which will contain the centres of pressure of all the vanes or buckets at all levels ofasuch a wheel, should have the arc of a parabola, with vertical axis for a generatrix, and a horizontal circle for a directrix, the

relative dimensions of which must vary with every.

case'.

To show more precisely how to'determine the proper diameter of the upper drum at any point, reference is .had to iig. 2. `The diameters' of the iimer and outer the location of 'the wheehan'd hence the velocity' of water due to that height may be computed.

centre of pressure of the vane or bucket at the level ofthe required diameter, as at g h, is made to hold the same ratio to the velocity due to the height of water due to the hydrostatic head at the level of the said diameter at g h, that the "radial distance l o from the axis to the centre of pressure of the vane or bucket at the level of the said radial distance l o, holds tothe velocity of water due to the height of water or hydrostatic head at such level.

The drum rfa'tis then made to conform to this proportion, being governed by the width ofthe vanes or buckets. The wheel constructed in this shape will provide that the actual circumferential velocity 'at cashpoint on the average or mean spiral (locus of centres of pressures oi' all levels) shall be directly proportional to the velocity of water due to the height of water or hydrostatic head at such point, as above required. 'lhe particles of water will then always act upon portions of the' vanes or buckets, the relative velocity ofwhiclnas the wheel turns under the influence. of the same, will be constant, compared with the velocity of said particles, thus preventing the dragging around of the upper particles between the vanos or buckets by'the superior forceot' the lower particles, and a waste of water-power.

I do `not intend to confine my invention strictly to the above proportion, but, however, aim in all cases toso diminish the diameter' of the upper ,drum as to sec-ure the advantage, or a portion thereof, above named. The shape of wheel to secure the best rcsults, must be iliade to vary with theY height of tall available.

This shape of wheel I deem especially applic. ble to low falls, for which I make the height of the wheel equal to that of the fall, thus putting the head rt level with the surface of the supply-stream.

Algebraic Expression for Diameter o f-,Dru-m.

` orinclination with the horizontal plane, that, as nearly -as possible, a drop of water will fall down along the line t q, in the same time that the point p will, by the revolution of the wheel, travel along the are p qto the point q. Therefore compute the average velocity of a drop of water falling down along the' line t q, and

also the actual circumferential velocity of the point p. The former,V divided by the line t q, should equal the latter divided by the arc p q, from which relation the angle or inclination of the vanes or buckets can be determined.

Algebraic Expression for the Arc p .11g-fil YH Te XIh 1) vh. q. There Vc actual circumierential velocity of the point p.

lVhere Vll z average velocity of descent along,r the line t q oi" a drop of water. p

In (his way an approximation may be made to the best position for the vanes. The most economical angle for the vanes may be computed by the wellknown principles of applied mechanics, as applied to turbine water-wheels.

Thus constructed, the wheel is stepped into the chamber or case L L. This case is either open or closed at the top, as the fall is low or high, and open at the bottom. The diameter of the lower opening is slight-ly smaller than that of the outer wall or rim of the annular drum, so that when the wheel is stepped, the outer wall er rim of the said annular drum sits up against the Hoor or bottom ofthe chamber, thus preventing an escape ot' water save through the passages between the vanes or buckets. The chamber is provided with one or more horizontal spiral lumes or water-leads of such shape as to lead the water economically upon the wheel in accordance with wellestablished principles ofturbine water-wheels. There the shalt.

C' latins.

\Vliat I claim as my invention, and desire to secure vby Letters latent, is-

1. A turbine water-wheel with varyingl diameter, diminishing from bottom to top, 4of form and construe tion substantially as above described and for the purposes set forth.

2. The combination ofthe upper drum with diminishing diameter from bottom to top, marked 'rfft in the drawings, with the' lower or annular drum, marked 'v o in the drawings, and with the continuous vanes winding spirally from the lower around the upper drum, substantially as above described and for the pur- H. C. JOHN HUDSON, J. Seor'r.

is a pivot at P, and a guide at G, for. the reception oi' 

